Leptis or Leptis Magna, also known by other names in antiquity, was a prominent city of the Carthaginian Empire and Roman Libya at the mouth of the Wadi Lebdam in the Mediterranean.
Originally a 7th-century BC Phoenician foundation, it was greatly expanded under Roman Emperor Septimius Severus (r. 193–211), who was a native of the city. The 3rd Augustan Legion was stationed here to defend the city against Berber incursions. After the legion's dissolution under Gordian III in 238, the city was increasingly open to raids in the later part of the 3rd century. Diocletian reinstated the city as provincial capital, and it grew again in prosperity until it fell to the Vandals in 439. It was reincorporated into the Eastern Empire in 533 but continued to be plagued by Berber raids and never recovered its former importance. It fell to the Muslim invasion in c. 647 and was abandoned.
Its ruins are within present-day Khoms, Libya, 130 km (81 mi) east of Tripoli. They are among the best-preserved Roman sites in the Mediterranean.
The Punic name of the settlement was written LPQ (Punic: 𐤋𐤐𐤒) or LPQY (𐤋𐤐𐤒𐤉). This has been tentatively connected to the Semitic root (present in Arabic) LFQ, meaning "to build" or "to piece together", presumably in reference to the construction of the city.
This name was hellenized as Léptis Megálē (Greek: Λέπτις μεγάλη, "Greater Leptis"), distinguishing it from the "Lesser Leptis" closer to Carthage in modern-day Tunisia. It was also known by the Greeks as Neápolis (Νεάπολις, "New Town"). The latinization of these names was Lepcis or Leptis Magna ("Greater Leptis"), which also appeared as the "Leptimagnese City" (Latin: Leptimagnensis Civitas). The Latin demonym was "Leptitan" (Leptitanus). It was also known as Ulpia Traiana as a Roman colony. Its Italian name is Lepti Maggiore; its Arabic name, Labdah (لَبْدَة).